The present invention relates to homo- and/or co-polymers and to thermoplastic moulding compositions having improved mechanical properties, and to the use thereof.
Thermoplastic moulding compositions, especially those containing homo- and/or co-polymers of one or more ethylenically unsaturated monomers, polycarbonates and polyesters, are known from a large number of publications. This is true especially of the use of ABS polymers. Reference is made to the following documents solely by way of example: DE-A-196 16 968, WO 97/40 092, EP-A-728 811, EP-A-315 868 (=U.S. Pat. No. 4,937,285), EP-A-0 174 493 (U.S. Pat. No. 4,983,658), U.S. Pat. No. 5,030,675, JA-59 202 240, EP-A-0 363 608 (=U.S. Pat. No. 5,204,394), EP-A-0 767 204, EP-A-0 611 798, WO 96/27 600, EP-A-0 754 531.
It is known from the prior art to filter polymer lattices in order to remove impurities or coarse portions. For example, Houben Weyl XIV/1, Makromolekulare Stoffe 1, pages 348 to 356 (Georg Thieme Verlag, Stuttgart, 1961) and DE-A-4 126 483 and U.S. Pat. No. 4,747,959 describe the filtration of rubber lattices. Connections with the mechanical properties are not known from that prior art.
Thermoplastic moulding compositions having a particle diameter of from 0.20 to 0.35 xcexcm are known from EP-A-0 704 488. A connection with elongation at tear, thermostability, natural shade and notched bar impact strength is not to be found in that prior art.
Accordingly, the object of the present invention is to make available homo- and/or co-polymers which are distinguished by improved mechanical properties, especially in respect of elongation at tear, thermostability, natural shade and notched bar impact strength, and by an especially consistent product quality.
That object is achieved by homo- and/or copolymers of one or more ethylenically unsaturated monomers (xe2x80x9cvinyl monomersxe2x80x9d) selected from the group of the mono- or poly-unsaturated olefins, such as ethylene, propylene, chloroprene, 1,3-butadiene, isopropene, vinyl acetate, styrene, xcex1-methylstyrene, styrenes substituted at the nucleus, vinyl cyanides, such as acrylonitrile, methacrylonitrile, maleic anhydride, N-substituted maleimides, C1-C8-alkyl acrylates and methacrylates, such as methyl acrylate and methyl methacrylate, which contain xe2x89xa6100 ppm of coarse portions having mean particle diameters of from 200 to 500 xcexcm. Special preference is given to coarse portions in amounts of xe2x89xa650 ppm, especially xe2x89xa610 ppm.